What does a process do when it wants to send data over the Internet?

(Many answers may apply.)

Source S sends packet P1, then packet P2 to destination D. The two packets traverse the same path (the same sequence of links and network devices). There is no other traffic on the Internet. P1 takes significantly longer than P2 to arrive. Which is the dominant delay component for packet P1?

What does it mean that two ISPs are "peering" with each other?

Could the Internet work without Internet eXchange Points (IXPs)?

Your home network infrastructure consists of a wireless router/modem connected to the Internet over a (traditional land) phone line. Your and your mom's computers are connected to the Internet through this wireless router/modem. 

You observe that downloading Netflix movies over the Internet becomes significantly slower than usual every Saturday night. What are plausible reasons?

(Many answers may apply.)

On a 64 bits architecture, what does the following code print ?

  const char* s = "123456";
  printf("%zu\n", sizeof(s));

Note: "%zu" is indeed the correct way to print values of size_t type.

What does the following code excerpt print?

  int tab[] = { 2, 4, 6, 8, 10, 12 };
  putchar('1');
  int a = -1;
  int* p = tab + 2;
  while ((a = *p++) < 10) { printf("%d", a); }

Considering

 What happens if a system crashes while writing data without crash consistency mechanisms?

Which statement(s) is/are TRUE regarding the structure of two-level indexing?